<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #result {
            width: 300px;
            height: 100px;
            border: solid 1px #903;
          }
    </style>
</head>
<body>
    <div id="result"></div>
    <script>
        const result = document.getElementById('result');
        //绑定键盘按下事件
        window.onkeydown = function(){
            //创建对象
            const xhr = new XMLHttpRequest();
            //设置响应体数据类型
            xhr.responseType = "json";
            //初始化
            xhr.open('GET','http://127.0.0.1:8000/json-server');
            //发送
            xhr.send();
            //事件绑定
            xhr.onreadystatechange = function(){
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                    if(xhr.status >=200 && xhr.status <300){
                        // console.log(xhr.response);
                        //返回结果
                        // result.innerHTML = xhr.response;
                        //手动对数据进行转换
                        // let data = JSON.parse(xhr.response);
                        // console.log(data);
                        // result.innerHTML = data.name;
                        //自动转换
                        console.log(xhr.response);
                        result.innerHTML = xhr.response.name;
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                }
            }
        }
    </script>
</body>
</html>